Blade and cover blind shutter



y 8, 1947' M. R. HUTCHISON, JR

BLADE AND COVER BLIND SHUTTER Fil ed Oct. 12', 1945 2 Sheets-Sheet 1" Nm m w. R m m M E m 0 w A July 1947- M. R. HUTCHISON, JR

BLADE ANDCOVER BLIND SHUTTER Filed Oct. 12, 1945 2 Sheets-Sheet 2 FIG.5.

FIG.4.

IN V EN TOR ATTORNEYS MILLER R.HUTCHISON.JR

Patented July 8, 1947 BLADE AND COVER BLIND SHUTTER Miller R. Hutchison,Jr., Rochester, N. Y., as-

signor to Eastman Kodak Company, Rochester, N. Y., a corporation of NewJersey Application October 12, 1945, Serial No. 622,028

6 Claims. 1

This invention relates to photography and more particularly to simpletypes of photographic shutters, particularly adapted for inexpensivecameras. One object of my invention is to provide a shutter of the classdescribed in which the shutter blade may be moved comparatively slowlyand with certainty. Another object of my invention is to provide ashutter of the class described in which a starting impulse is applied tothe shutter blade to insure starting movement of the shutter blade. Astill further object of my invention is to provide a shutter which isinexpensive and which will produce the required comparatively longautomatic exposure generally used with so-called single lenses which areusually meniscus or meniscus achromatic lenses having a small diaphragmopening.

In inexpensive shutters, the parts are ordinarily made frompunch-pressed sheet metal parts which are ordinarily lacquered, ortreated with a suitable rustproofing process, so that it is not alwayseasy to reduce friction to a point where a required comparatively slowexposure, such as /2 of a second, can be reliably obtained. It isordinarily a simple matter to move a shutter blade slowly enough forsuch an exposure if a relatively weak spring is used, but such Springsare not ordinarily reliable because they do not have suflicient power toovercome the friction of the shutter blade in starting. My invention isparticularly directed to overcoming these diiliculties without anappreciable addition to the number of parts used in the shutter.

Coming now to the drawings wherein like reference characters denote likeparts throughout:

Fig. l is a rear elevation of a shutter, with certain parts removed forclearness, as it would appear looking from the inside of the cameraoutwardly; the parts being shown in a normal position of rest;

Fig. 2 is a view similar to Fig. 1 but with the parts shown as theyappear just before an exposure is made;

Fig. 3 is an enlarged fragmentary detailed section with certain partsbeing shown in elevation;

Fig. 4 is a view similar to Fig. 1 but with the parts as they appearafter an exposure is completed;

Fig. 5 is a view similar to Fig. 1 but with the shutter open for aprolonged exposure;

Fig. 6 is a detail section taken on line 66 of Fig. 4; and

Fig. 7 is a rear elevation of a shutter constructed in accordance with asecond embodiment of my invention.

My invention consists broadly in providing an inexpensive shutter of aso-called blade-andcover-blind type and in so arranging the cover blindthat it both releases the shutter blade spring and, in addition, itimparts a starting influence to the shutter blade. This shutter differsfrom the customary type of blade and shutter blind cover in that whilethe cover blind is moved, through movement of the trigger, it does notmove with the trigger but includes a separate spring which is tensionedand released through movement of the trigger.

More specifically, as indicated in Fig. 3, my shutter may cOnsiSt of asupport I which is apertured at 2, this aperture constituting anexposure aperture. There is a stud 3 extending through to both sides ofthe support I. This stud oscillatably supports a shutter blade 4 on oneside and cover blade 5 on the opposite side. Thus, both these movableplates may be carried coaxially on the single stud 3. This not onlyfacilitates assembly but provides a substantial arrangement for properlypositioning the two plates.

The shutter blade 4 is here shown as consisting of a thin punch-pressedsheet metal part having an elongated slot or opening 6 adapted to coverand uncover the exposure aperture 2 in swinging upon the stud 3 to makean exposure. In its normal position of rest, shown in Fig. 1, the slot 6is spaced from the exposure aperture 2 quite a material distance and itshould be noticed that the exposure aperture 2 is also covered by thecover blind 5, The cover blind 5 is also pivoted on the stud 3 and mayswing to and from a position covering the exposure aperture 2.

A trigger I is provided, this trigger in the present instance beingslidably mounted in the ears 8 of a bracket 9 which may be attached tothe support I in any suitable manner. A spring [0, pressing against oneear 8 and a shoulder or protuberance I I on the trigger, tends to holdthe trigger outwardly in the position of rest shown in Fig. 1. Thetrigger consists of two main portions, the rod 1 and a small segment I2,which is mounted to swing upon the stud I 3 carried by the support I.This swinging movement carries a pin [5 through a path which intersectsthe radial lines A--B, shown in Fig. 1, line A being a line drawnbetween the stud 3 which supports the cover blind 5 and a stud H on theshutter blade. Line B is drawn between a pin [8 on the cover blind andthe stud 3. The stud I1 and pin l8 are angularly offset as indicated inFig. 1 so that the cover blind 5 will move before the shutter 3 blade 4as will be more fully described hereinafter.

The pin l5, carried by the trigger section [2, carries one end of twosprings. The spring 20 is the shutter blade spring and includes one end2! connected to the pin l5, and the other end 22 connected to the studH. The spring 24 has one end 24a connected to the pin 15 and the otherend 242) connected to the pin l8. In the preferred form of my invention,the spring 24, which is the cover blind spring, is more powerful thanthe spring 28 which is the shutter blade spring, the power of the twosprings being easily controlled by selecting the proper diameter ofwire.

The two trigger parts 7 and I2 ar operably connected by a pin 4c carriedby the trigger l and a slot 4! in the trigger segment l2 so that thesetwo parts in the embodiment shown in the drawings always move togetheras a unit.

When the trigger 1 is depressed and the pin l swings through its arcuatepath, it will, of course, tension both the spring 20 and th spring 24simultaneously. However, because of the onset angle between the lines Aand B, the movement of the trigger will release the spring 2d, which isthe cover blind spring, when the stud it passes the dead centerindicated by the line A of Fig. 1. Thus, the cover blind 5 will start tomove before the shutter blade 4. The starting movement of the coverblind is shown in Fig. 2 in which position the pin 55 is just reaching aposition in which the spring 20 may be released to drive the shutterblade 4 through its path of movement to make an exposure.

Since the spring 2% is more powerful than spring 28, I provide a meansfor initiating movement of the shutter blade 4 operated by the coverblind, In the present instance, this means is a pin-and-slot connectionwhich is formed by the pin i7 extending from the shutter blade through aslot 25 in the cover blind, this slot also having a counterpart at 28 inthe supporting plate I, enabling this lost-motion connection between thecover blind and shutter blade to perform its function.

Referring to Fig. 2, it will be noticed that the pin l'i' has struck theend 2"! of the slot 25, thus engaging and moving the shutter blade t.From the position shown in Fig. 2, the cover blind and shutter bladewill move together until a lug 23 on the cover blind reaches the springstop 29 carried by a. suitable camera part 30. When this occurs, thecover blind 5 will cease moving and the shutter blade 4 will continue tomove under the power of its weaker spring 20 until the pin E7 on theshutter blade also reaches the end of slot 25 in the cover blind 5.

From the abov description it will be noticed that when the trigger l isdepressed the proper distance, springs 28 and 2d will be tensioned andspring 24 will be released. The releasing of this spring causes thecover blind to move until the pin ll strikes the end 2'5 of the slot 25,giving the shutter blade 4 a push and moving with the shutter blade 2.short distance to insure proper starting of the shutter blade. However,th force of the spring 24 is largely consumed in starting the shutterblade 4, so that it slows up and moves with the shutter blade a shortdistance, or until the cover blind reaches its stop, at which time theshutter blade 4 proceeds under its own spring 20 to complete itsmovement. Thus, I am able to obtain comparatively slow movement of theshutter blad 4 without any liability of un- 4 certainty in starting themovement of this blade through its Weak spring.

When the shutter trigger l is released, the spring It will restore thetrigger to its initial position of rest, shown in Fig. 1, and since thespring Ill has considerably more power than the combined strengths ofthe springs 25 and 24, it will again set and release these springs sothat they may both return to their initial position. However, during thereturning movement, the cover blind 5 moves in advance of the shutterblade 4 and covers the exposure aperture 2 before the exposure opening 6of the shutter blade begin to uncover and then cover the exposureopening 2.

As indicated in Fig. 1, a time stop 32 is provided on wall 30 which canbe moved from the inoperative position Fig. l to an operative positionin Fig. 5 in which position it may engage shutter blade lug 3 I. When sopositioned it will stop the shutter blade 4 with the opening 6 over theexposure aperture 2, Releasing the shutter will cause the shutter partsto move in a re verse direction and to their Fig. 1 position of restterminating the prolonged exposure, or if desired the time stop may bemoved by a suitabie handle, not shown, in which case movement of theblade in the same direction would take place until the exposure opening2 is closed. Such tim stops are known and this stop forms no part of thepresent invention.

While I have described a preferred embodiment of my invention, it isobvious that various changes can b made therein without departing frommy invention. I ha e shown, for instance, a slidably-mounted triggersince such triggers appear to be in particular favor at this time. It isvery obvious that a further simplification of the shut ter could occurby omitting entirely the sliding trigger l and providing a pivoted oneas in Fig. 7. As shown herein, the shutter blade 4 may be the same asbefore as also is the cover blind 5, but the trigger 59 is pivoted at Eland is unlike and simpler than trigger l. Springs 52 and 53 attached tothe shutter blade 6 and cover blind 5 are also attached to a stud 54carried directly by the trigger 52.

Both embodiments of my invention provide a blade and cover blind type ofshutter in which the cover blind is difierent from the usual cover blindin being operated, not directly by the trigger but by being indirectlyoperated through a spring. In addition, the cover blind imparts astarting impulse to the shutter blade, permitting a light sprin tocontinue the movement of the shutter.

I claim:

1. A camera shutter comprising an apertured support, a shutter bladepivotally mounted thereon for movement to uncover and cover saidaperture to make an exposure, a cover blind pivotally mounted on thesupport for movement to uncover and cover said aperture, a triggermovably mounted on the support, a shutter blade spring connecting theshutter blade and trigger, a cover blind spring connecting the coverblind and trigger, said trigger setting both springs by moving saidsprings as the trigger is moved, the connections between the cover bladespring and the cover blade, and the cover blind spring and cover blindbeing angularly offset with respect to the pivotal mounts of the shutterblade and cover blind whereby movement of the trigger may be set bothsprings and release only the cover blind spring and means carried by thecover blind for releasing the shutter blade spring whereby the shutterblad may swing upon its pivot to make an exposure.

2. The camera shutter defined in claim 1 characterized by both springsbeing of hairpin shape.

3. The camera shutter defined in claim 1 characterized by the means forreleasing the shutter blade spring carried by the shutter bladeincluding a means for contacting with and moving the shutter blade tostart movement thereof.

4. The camera shutter defined in claim 1 characterized by the means forreleasing the shutter blade spring carried by the shutter blade including a means for limiting the movement of the shutter blade relative tothe cover blind.

5. The camera shutter defined in claim 1 characterized by the shutterblade and cover blind being coaxially mounted and by th means forreleasing the shutter blade spring consisting of a pin-and-slotconnection between the coaxiallymounted shutter blade and cover blind.

6. A camera shutter, comprising an apertured support, a shutter bladepivoted to the support for movement to uncover and cover said apertureto make an exposure, a cover blind pivotally mounted on the support formovement to uncover and cover the exposure aperture, a shutter triggermovably mounted on the support, a spring connecting the trigger andshutter blade, a second spring connecting the trigger and cover blind,said trigger simultaneously setting said springs and releasing the coverblind spring after setting, a pin-and-slot connection between theshutter blade and cover blind through which said set and released coverblind may initiate movement of the shutter blade and release th springthereof whereby said shutter blade, traveling under the impulse of itsown spring, may make an exposure.

MIILER R. HUTCHISON, JR.

I Certificate of Correction 'wtent No. 2,423,706. Jul 8, 1947. MILLER R.HUTOHISON, JR,

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Column 4,line 74, claim 1, for the Words may be set read may set; and that thesaid Letters Patent should be read With this correction therein that thesame may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of September, A. D. 1947.

[SEAL] LESLIE FRAZER,

First Assistant Commissioner 0 1 Patents.

Certificate of Correction i iitent No. 2,423,706. July 8, 1947. MILLERR. HUTCHISON, JR

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Column 4,line 7 4, claim 1, for the Words may be set read may set; and that thesaid Letters Patent should be read with this correction therein that thesame may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of September, A. D. 1947.

LESLIE FRAZER,

First Assistant Gammissz'oner 0 f Patents.

